John Deere A oil leak?

jdajason

New User
Have a question. I was inspecting some tappet noise on my 1950 John Deere A & found there was no oil getting to the tappet area. I have since gotten oil to pump to the tappet oil outlet that bolts to the head but have another problem. It will not pump up the tube to drip out of the ends. Instead it leaks out of the bottom of the oil outlet. I have tried using anaerobic sealer to seal this up & it still leaks. I have checked both surfaces with a straight edge & they appear flat. My step dad mentioned that I need to un-screw the crank case oil filler cap because of the pressure & it still leaks. It does not leak out of the tube fitting. Question is a dumb one but is it suppose to leak? The reason I ask that is I know it needs to return to the crank case so there is a hole some where (not sure where). Note: I have not put the tappet cover on yet & checked it. Should I try that & check it? I have attached a couple of photos. Thanks for the help/advice!
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There are 2 different types of those oil lead washers used. The head casting number and the parts book will help. I cannot see from these pics what you may need. Take a pic of the cyl. head with the washer removed showing the oil feed and return passages.
 
Are you sure that the oil line to the tappets is clear? I would soak it in lacquer thinner and make sure the passage is clear. Also I would take the part you have sitting on the can and put a piece of 1000 grit sandpaper on a piece of glass and sand ever so slightly to make sure that the surfaces are true.
 
Have you sealed off the oil tube with that sealing stuff you put in there? Also, seems like that copper washer should be under the bolt head, not inside the oiler housing.
 
The tappet oil tube is twisted just above the nut. Easy to do when taking those fittings off. Make sure it isn't pinched or plugged up. There should be very little pressure in that line to cause the washer to leak. The oil returns to the crankcase through a cast-in passage just below the washer. You can just see the edge of it in the first picture.
 
Mike M is on the right track. You need the other oil washer from what you have. I see "A4" in the picture, so you have a A4226R head, which takes the "D" shaped oil washer and not the round one you have. The round one you have fits the early heads. On the early heads, the oil feed hole is directly under the center head stud hole and then the drain slot is under the pressure hole. On your head, the oil pressure hole should be at about the 4 o'clock position and the drain slot directly under the center head stud hole. Yours is probably leaking because the oil washer is partially overlapping the drain slot.
 
Thank you for the replies. The copper washer is between the head nut and oil outlet in the photo. When I rebuilt the engine I mistakenly put the washer betweem the outlet and the head. Didn't realize I had installed it incorrectly until I investigated this issue and have since corrected it. The oil tube is clear. I am able to pump oil through it with a little oil can. The picture of the outlet and washer was after I had tried to seal it with RTV which didn't work. I carefully scraped the gasket off and used scotch bright pad to finish clean it. I have attached a photo of my original head off the tractor. Same part number as what is currently on it.

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That makes sense Drew & Mike. So the even with the crank case cap off like my step dad suggested it still has pressure because the oil return is blocked creating pressure forcing oil backwards up the return. I am in Nashville for a couple of days but have looked into this "D" shaped outlet & attached a photo of one. Based on the oil pressure hole & the return on my head this is definitely the one I need. I will try to locate one & put it on. Not sure how this wrong outlet ended up on the tractor. Thank you every one for help, it is much appreciated!
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